Facile high yielding synthesis of symmetric esters of methylenebisphosphonic acid
摘要:
The 1H-tetrazole catalyzed coupling of methylenebis(phosphonic dichloride), CH2(POCl2)(2), with primary alkyl, cyclic secondary alkyl, aromatic, and silicon- and fluorine-containing alcohols selectively affords symmetric P,P'-dialkyl partial esters as wen as homoleptic and mixed tetraesters. Two partial ester intermediates, methylenebis(2-ethylhexyl phosphonic chloride) and 2-ethylhexyl methylenebisphosphonic trichloride, were observed by H-1- and P-31 NMR spectroscopy in the esterification of CH2(POCl2)(2) with 2-ethyl-1-hexanol. (C) 2001 Elsevier Science Ltd. All rights reserved.